CN101662840B

CN101662840B - Method for measuring GSM reconfirmation in TDD mode

Info

Publication number: CN101662840B
Application number: CN2008100421467A
Authority: CN
Inventors: 沈凡
Original assignee: Leadcore Technology Co Ltd
Current assignee: Leadcore Technology Co Ltd
Priority date: 2008-08-28
Filing date: 2008-08-28
Publication date: 2012-01-11
Anticipated expiration: 2028-08-28
Also published as: CN101662840A

Abstract

The invention discloses a method for measuring the GSM reconfirmation in a TDD mode, which has a simple algorithmic procedure and a precise measurement result. The technical sachem is that the method comprises the following steps: updating a last time synchronizing time point according to the period number with the length of 3.06 seconds existing between the last time synchronizing time point and a current time point; by taking 1/13 or the length of a TDD frame as a timing unit delta, converting the offset in the TDD frame of the last time synchronizing time point into a delta number and the offset in the delta, and converting the offset of a known idle window in the TDD frame into the delta number; and according to the remainder of a model 51 of a GSM frame number of the last time synchronization and according to an expected position of a synchronization pulse in the TDD frame, calculating the frame number difference of the GSM frame number between the last time synchronizing time point and the next time synchronizing time point, and converting the frame number difference into the TDD frame number difference and the intra-frame offset. The method is applied to mobile communication.

Description

The method that measure GSM is heavily confirmed under a kind of tdd mode

Technical field

The present invention relates to the method for measurement of lock in time, relate in particular under the simple and accurate tdd mode of a kind of algorithmic procedure the method for measurement of heavily confirming is done in the GSM sub-district.

Background technology

For providing bimodulus ambulant support to the terminal, need do regular measurement to the information of adjacent cells of the GSM the terminal near, there are some measurement results also need report network side, to support gravity treatment and handoff functionality.Heavily confirm it is the measurement item that contains cell synchronization information; The heavy confirmation that a GSM sub-district has been arranged; In the time of just can or switching, realize and the time synchronized of switching target small area that it is to realize through the SB (lock-out pulse) that reception GSM network sends in the needs gravity treatment.

Known implementation has two kinds; First kind is to utilize for known 13 * 51 cycle, and configuration SB heavily confirms (in A2000+, using) in the fixed position, this scheme since the cycle long; The fixed position is not necessarily idle again, and SB need heavily to confirm the long period just can do once.Another kind is because the remainder that the SB frame number satisfies mould 51 can be 1,11,21,31 or 41; Utilize the position of known SB; Travel through each and drop on the GSM frame in the idle window (also becoming idle time slot), find the remainder that satisfies mould 51 is 1,11,21,31,41 GSM frame always.Because the GSM frame that contains SB has been found in the computing that needs circulation to do mould 51, and the GSM frame that contains SB that finds possibly pass by, then need recomputate, so the shared MIPS of the algorithm of this circulation delivery is very considerable.

To sum up, under TD-SCDMA, will realize the heavily affirmation of the adjacent sub-district of GSM, be in order to realize the switching (promptly switching to GSM sub-district, dual mode capability from the TD sub-district) between TD system and the gsm system, wherein has following major technology difficult point:

(1) frame structure of GSM and TD is different, and frame length is different, makes relatively difficulty of signal that ad-hoc location (any one or more idle time slots) in the time system of TD receives ad-hoc location in the GSM time system;

(2) the power saving problem of terminal equipment and optimization Algorithm are the problems that must consider, so shared MIPS (instruction number) must be few more good more when receiving the GSM signal, can not carry out by traffic affecting;

(3) because the frame length of two systems is different; (the frame number difference takes advantage of 12 again except that 13 merchant to have time error when converting each other between two kinds of number systems; How many tail significant figure errors all can be very big after when the frame number difference is very big, keeping how many decimal points); And regularly precision is had requirement, thus possibly cause fatal problem, so the processing of division remainder is very difficult.

Summary of the invention

The objective of the invention is to address the above problem, the method that measure GSM is heavily confirmed under a kind of tdd mode is provided, algorithmic procedure is simple and measurement result is accurate.

Technical scheme of the present invention is: the present invention has disclosed the method that measure GSM is heavily confirmed under a kind of tdd mode, is used to calculate the lock in time of tdd frame and GSM frame, and this method comprises:

(1) is 3.06 seconds number of cycles according to there being length last time between synchronizing time point and the current point in time, upgrades synchronizing time point last time;

(2) with tdd frame long 1/13 be time of day delta, with the side-play amount in the tdd frame of synchronizing time point last time convert to delta number and delta in side-play amount, and the known side-play amount of idle window in tdd frame converted to delta number;

(3) according to the remainder of last hyposynchronous GSM frame number mould 51 and the desired locations of lock-out pulse in tdd frame calculate last time synchronizing time point and next synchronizing time point between the frame number of GSM frame number poor, convert this frame number difference in tdd frame difference and the frame side-play amount.

The method that measure GSM is heavily confirmed under the above-mentioned tdd mode; Wherein, In step (1); Was to be extended down to backward in the cycle from the current point in time less than till 3.06 seconds known historical lock in time with 3.06 seconds, after promptly upgrading last time synchronizing time point and current point in time between the time interval be no more than 3.06 seconds.

The method that measure GSM is heavily confirmed under the above-mentioned tdd mode, wherein, the calculating GSM frame number difference in the step (3) further comprises:

The remainder a of hyposynchronous GSM frame number mould 51 in the calculating;

According to formula (a+b) mod51=1,11,21,31,41 with the value of remainder a, the value of calculating parameter b, wherein parameter b is two the remainders of GSM frame number differential mode 51 between subsynchronous;

Value according to parameter K value and the definite desired locations n of lock-out pulse in tdd frame of H value; Wherein on behalf of the frame head of going up hyposynchronous GSM frame, the parameter K value drop on K the time of day delta of tdd frame; The Parameter H value is represented on H the timing unit delta of idle window in current tdd frame; Confirm that mode is: if (H-K)>0 then n=13-(H-K) is if (H-K)≤0 then n=K-H;

Try to achieve the value of parameter m according to the value circulation delivery of parameter b and n.

Table look-up according to the value of parameter b and n and to try to achieve the value of parameter m.

The method that measure GSM is heavily confirmed under the above-mentioned tdd mode, wherein, table look-up and ask the form in the parameter m value to be:

n/b	0	10	20	30	40	11	21	31	41
										0	51	40	29	18	7	44	33	22	11
1	47	36	25	14	3	40	29	18	7
										2	43	32	21	10	50	36	25	14	3
3	39	28	17	6	46	32	21	10	50
										4	35	24	13	2	42	28	17	6	46
5	31	20	9	49	38	24	13	2	42
										6	27	16	5	45	34	20	9	49	38
7	23	12	1	41	30	16	5	45	34
										8	19	8	48	37	26	12	1	41	30
9	15	4	44	33	22	8	48	37	26
										10	11	0/51	40	29	18	4	44	33	22
11	7	47	36	25	14	0/51	40	29	18
										12	3	43	32	21	10	47	36	25	14

The method that measure GSM is heavily confirmed under the above-mentioned tdd mode, wherein, the side-play amount that in the step (3) the frame number difference is converted in tdd frame difference and the frame further comprises:

According to parameter m value and n value calculate last time synchronizing time point and next synchronizing time point between the frame number of GSM frame poor, thereby obtain the corresponding GSM frame number of next synchronizing time point, computing formula is: the GSM frame number is poor=13 * m+n;

GSM frame number difference is changed into the side-play amount in tdd frame number and the tdd frame.

The method that measure GSM is heavily confirmed under the above-mentioned tdd mode, wherein, the side-play amount that GSM frame number difference is changed in tdd frame number and the tdd frame further comprises:

Calculate the corresponding tdd frame ntdsfn of next synchronizing time point according to the value of parameter K, n and m; Account form is: if n=0 then ntdsfn=ltdsfn+12 * m; If K>=n and n ≠ 0 then ntdsfn=ltdsfn+12 * m+n; If K is<n and n ≠ 0 then ntdsfn=ltdsfn+12 * m+n-1; Wherein ltdsfn is the corresponding tdd frame of synchronizing time point last time number, calculate in the tdd frame bias internal amount next_td_offset=H * delta+ step (2) of next synchronizing time point last time synchronizing time point the conversion of tdd frame bias internal amount after delta in side-play amount.

The present invention contrasts prior art has following beneficial effect: the present invention is new time of day delta with 1/13 of tdd frame length; And find optimal m value (intermediate parameters) fast through look-up table; Avoid doing the computing of cyclic module 51 but accurately draw and wait to ask the frame number of GSM frame number and reference frame poor through doing simple multiplication and add operation; It is poor to convert out corresponding tdd frame through simple judgement and once linear multinomial (c*x+d) again, and precision is very high.Method of the present invention can be calculated the position of all rebsic rapidly and accurately, and the taking seldom of MIPS.

Description of drawings

Fig. 1 is the flow chart of the preferred embodiment of the method that measure GSM is heavily confirmed under the tdd mode of the present invention.

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is done further description.

The method that measure GSM is heavily confirmed under the tdd mode of the present invention is the known side-play amount last_td_offset (span 0～6400 in frame number is the tdd frame of last_td_subframe_number (ltdsfn) once; The chip of unit) place receives SB (the Special Burst in the GSM frame that the GSM frame number is last_gsm_frame_number (lgfn); Special burst); And known current tdd frame number be current td_subframe_number (ctdsfn) and after the ctdsfn frame idle condition of time slot in each frame; Obtain the SB that receives GSM in the earliest can idle time slot behind the ctdsfn frame, please obtain the frame number netx_gsm_frame_number (ngfn) of the GSM frame at this SB place at which tdd frame.

The physical quantity that relates in the present invention is described below:

It is following wherein to import physical quantity:

1, the GSM frame number lgfn at the SB that once received place and once received the tdd frame ltdsfn of SB and the position last_td_offset (span 0～6400, unit is chips) in this tdd frame;

2, the current frame number ctdsfn of TDD;

3, idle time slot (or being called idle window) Free_window_bitmap in the frame.The output physical quantity is following: the nearest TDD frame number next_td_subframe_number (ntdsfn) that can in idle window, receive SB next time; Receiving position next_td_offset (span 0～6400 with respect to the frame head of ntdsfn frame; And the frame number ngfn of the GSM frame at the SB that receives place the chips of unit).

Fig. 1 shows the flow process of the preferred embodiment of the method that measure GSM is heavily confirmed under the tdd mode of the present invention.Seeing also Fig. 1, is the detailed description to each step in this method below.

Step S10: according to there being length last time between synchronizing time point and the current point in time is 3.06 seconds number of cycles, upgrades synchronizing time point last time.

When carrying out high speed business under the tdd mode, as idle time slot occurring in a short time, will cause last time synchronizing time point and the current time differ too many.According to theoretical derivation, SB can repeat to occur at the same position of tdd frame with the cycle of 3.06 seconds (it is long to be equivalent to 613 tdd frames).

For the above reasons, be to be extended down to backward in the cycle from the current point in time less than till 3.06 seconds known historical lock in time with 3.06 seconds, after also promptly upgrading last time synchronizing time point and current point in time between the time interval be no more than 3.06 seconds.

Step S11: with tdd frame long 1/13 as time of day delta; With the side-play amount in the tdd frame of synchronizing time point last time convert to delta number and delta in side-play amount, and the known side-play amount of idle window (Free_window_bitmap) in tdd frame converted to delta number.

Because a tdd frame and the ratio of a GSM frame on time span are 13: 12, therefore defining 1/13rd tdd frame length is a time of day delta.And be that unit comes the conversion time with delta, delta is called GSM and the long common unit of tdd frame, between two systems, has set up an interoperation relationships.

Step S12: the remainder a that calculates last synchronous GSM frame number mould 51.

According to the agreement regulation, a remainder that comprises the GSM frame number mould 51 of SB only possibly be 1,11,21,31,41.

Step S13: according to formula (a+b) mod51=1,11,21,31,41 with the value of remainder a, the value of calculating parameter b, wherein (13 * m+n) mod51 are two remainders of GSM frame number differential mode 51 between subsynchronous to b=.

A=(lgfn) mod51 wherein; Because it is 1,11,21,31,41 that the GSM frame number lgfn at SB place satisfies the remainder value of mould 51, just can confirm by the value of a which value b gets

During a=1, get b=0,10,20,30,40;

During a=11, get b=0,10,20,30,41;

During a=21, get b=0,10,20,31,41;

During a=31, get b=0,10,21,31,41;

During a=41, get b=0,11,21,31,41.

Step S14: according to the value of parameter K value and the definite parameter n of H value.Wherein on behalf of the frame head of going up hyposynchronous GSM frame, the parameter K value drop on K the time of day delta of tdd frame; Removing delta by input variable last_td_offset obtains; The Parameter H value is represented on H the timing unit delta of idle window in current tdd frame and is confirmed by Free_window_bitmap; The H value of determining has a plurality of values, goes to table look-up according to the value of each H.

Confirm that mode is specially: be worth a K value method following by each H: if (H-K)>0 then n=13-(H-K) is if (H-K)≤0 then n=K-H.

Step S15: the value of trying to achieve a m according to the value of each b of parameter and n.

In one embodiment of the invention, can obtain the value of parameter m through the mode of circulation delivery according to the value of parameter b and n.

In another embodiment of the present invention, also can try to achieve the value of parameter m through the mode of tabling look-up according to the value of parameter b and n.Its essence is based on the thinking of circulation delivery and makes a form in advance, as long as the value of b and n has been arranged, through tabling look-up rather than in mobile phone, doing the value that the circulation delivery just can obtain m, can significantly reduce amount of calculation and computing time like this.

Since GSM frame number difference with (13 * m+n) expressions, just arbitrarily GSM frame number difference can be equivalent to 12 tdd frames of m long with n GSM frame length and.

Form is following:

In form, it is 0,10,20,30 that first row is represented the value of b, and it is 0～12 that 40,11,21,31,41, the first row are represented the value of n, and representative is the value of m in all the other frames, for example m=21 when b=20 and n=2.

Be to adopt the method for putting real-time computing time in the conventional art; Shortcoming is that amount of calculation is big and it is too many to take cpu resource; And the look-up table in the embodiment of the invention can reduce great amount of calculation; Especially can not do modular arithmetic, only need do multiplication, and can accurately find the nearest interior SB of idle window that drops on add operation gets final product.

And the description of face as follows of the origin of form:

If lgfn is mod51=a, ngfn mod51=c, wherein lgfn is the GSM frame number of synchronizing time point last time, ngfn is the GSM frame number of next synchronizing time point.

According to agreement, lgfn mod51=1,11,21,31,41, ngfn=lgfn+13 * m+n (integer of n=0 to 12, m are carry), the n value is decided by idle window position and the last position of GSM frame head in tdd frame when subsynchronous.

C=[lgfn mod51+ (13 * m) mod51+n] mod51, regard n as constant with the method for undetermined coefficients, then c is the periodic function of m, the m cycle is 51.Therefore (Fn-F1) can regard as integral multiple of 633 and divided by the remainder of 633 gained partly with.

Ask and satisfy ngfn mod51=1, the solution procedure of 11,21,31,41 ngfn is following.If (13 * m+n) mod51=b, and ngfn mod51=[a+ (13 * m+n) mod51] mod51=1,11,21,31,41 formula (1).

Wherein: a=1,11,21,31,41, like the formula (1) that will satisfy condition:

When a=1, get b=0,10,20,30,40;

When a=11, get b=0,10,20,30,41;

When a=21, get b=0,10,20,31,41;

When a=31, get b=0,10,21,31,41;

When a=41, get b=0,11,21,31,41;

Calculate to satisfy again that (13 * m+n) mod51=0,10,20,30,40,11,21,31,41 m value is according to the top form of these m values foundation when n satisfies during value 0 to 12 respectively.

Step S16: according to the value of parameter m and n calculate last time synchronizing time point and next synchronizing time point between the frame number of GSM frame poor; Thereby obtain the corresponding GSM frame number of next synchronizing time point; Computing formula be GSM frame number difference for (13 * m+n), ngfn=lgfn+13 * m+n just.

Step S17: calculate the corresponding tdd frame ntdsfn of next synchronizing time point according to the value of parameter K, n and m, calculate the tdd frame bias internal amount next_td_offset of next synchronizing time point.

Concrete account form is: if n=0 then ntdsfn=ltdsfn+12 * m; If K>=n and n ≠ 0 then ntdsfn=ltdsfn+12 * m+n; If<n and n ≠ 0 then ntdsfn=ltdsfn+12 * m+n-1, wherein ltdsfn is the tdd frame after last time, synchronizing time point was upgraded number to K.

And among next_td_offset=H * delta+ step S11 last time synchronizing time point tdd frame bias internal amount conversion after delta in side-play amount.

The foregoing description provides to those of ordinary skills and realizes or use of the present invention; Those of ordinary skills can be under the situation that does not break away from invention thought of the present invention; The foregoing description is made various modifications or variation; Thereby protection scope of the present invention do not limit by the foregoing description, and should be the maximum magnitude that meets the inventive features that claims mention.

Claims

1. the method that measure GSM is heavily confirmed under the tdd mode, the lock in time that is used to calculate tdd frame and GSM frame, this method comprises:

(1) be 3.06 seconds number of cycles according to there being length last time between synchronizing time point and the current point in time; Upgrade synchronizing time point last time; Be to be extended down to backward in the cycle from the current point in time less than till 3.06 seconds with 3.06 seconds wherein with known historical lock in time, after promptly upgrading last time synchronizing time point and current point in time between the time interval be no more than 3.06 seconds;

2. the method that measure GSM is heavily confirmed under the tdd mode according to claim 1 is characterized in that, the calculating GSM frame number difference in the step (3) further comprises:

Value according to parameter K value and the definite desired locations n of lock-out pulse in tdd frame of H value; Wherein on behalf of the frame head of going up hyposynchronous GSM frame, the parameter K value drop on K the time of day delta of tdd frame; The Parameter H value is represented on H the timing unit delta of idle window in current tdd frame; Confirm that mode is: if (H-K)＞0 then n=13-(H-K), if (H-K)≤0 then n=K-H;

Try to achieve the value of parameter m according to the value circulation delivery of parameter b and n, wherein GSM frame number difference is with (13 * m+n) expressions.

3. the method that measure GSM is heavily confirmed under the tdd mode according to claim 1 is characterized in that, the calculating GSM frame number difference in the step (3) further comprises:

Table look-up according to the value of parameter b and n and to try to achieve the value of parameter m, wherein GSM frame number difference is with (13 * m+n) expressions.

4. the method that measure GSM is heavily confirmed under the tdd mode according to claim 3 is characterized in that, tables look-up and asks the form in the parameter m value to be:

5. the method for heavily confirming according to measure GSM under claim 2 or the 4 described tdd modes is characterized in that, the side-play amount that in the step (3) the frame number difference is converted in tdd frame difference and the frame further comprises:

6. the method that measure GSM is heavily confirmed under the tdd mode according to claim 5 is characterized in that, the side-play amount that GSM frame number difference is changed in tdd frame number and the tdd frame further comprises:

Calculate the corresponding tdd frame ntdsfn of next synchronizing time point according to the value of parameter K, n and m, account form is:

If n=0 then ntdsfn=ltdsfn+12 * m;

If K >=n and n ≠ 0 then ntdsfn=ltdsfn+12 * m+n;

If K＜n and n ≠ 0 then ntdsfn=ltdsfn+12 * m+n-1;

Wherein: ltdsfn is the corresponding tdd frame of synchronizing time point last time number, calculate in the tdd frame bias internal amount next_td_offset=H * delta+ step (2) of next synchronizing time point last time synchronizing time point the conversion of tdd frame bias internal amount after delta in side-play amount.